Swim fins

ABSTRACT

Swim fins that attach to the legs of a swimmer to aid movement through the water. In one example embodiment, a swim fin includes an upper support frame, a lower support frame, a lower blade attached to the lower support frame, and at least one hinge assembly connecting the upper support frame to the lower support frame. The upper support is configured to be generally positioned along and attached to the front of a swimmer&#39;s lower leg between the swimmer&#39;s knee and ankle The lower support frame is configured to extend, in a swimming position, from a position proximate the swimmer&#39;s ankle to a position beyond the end of the swimmer&#39;s foot. The at least one hinge assembly allows the lower support frame to be rotated upward from the swimming position to a walking position. The walking position enables the swimmer to walk barefoot on a surface without the lower support frame nor the lower blade substantially contacting the surface.

CROSS REFERENCE TO A RELATED APPLICATION

This application claims priority to and the benefit of U.S. ProvisionalPatent Application Ser. No. 61/100,207, entitled SWIM FINS, which wasfiled on Sep. 25, 2008, and is hereby incorporated by reference in itsentirety.

BACKGROUND

1. Field of Invention

The present invention generally relates swim fins and, in particular, toswim fins that attach to the legs of a swimmer to aid movement throughthe water.

2. Description of Related Art

Typical swim fins are worn on the foot of a swimmer to aid movementthrough the water while surface swimming or participating inswimming-related activities such as bodyboarding, bodysurfing,kneeboarding, riverboarding, snorkeling, and various types of underwaterdiving. For example, scuba divers use swim fins to move through waterefficiently, as human feet provide relatively poor thrust, especiallywhen the diver is carrying equipment that increases hydrodynamic drag.

Unfortunately, typical swim fins have several problems. For example,since typical swim fins attach only to the foot and heel of a swimmer,typical swim fins can cause severe ankle strain and calf muscle fatigue.This is due to the mass of water moved by the fin and the fact that theankle joint rotates through a complex, non-planar, arc. Further, theankle does not generally orient the foot optimally for forward thrust,thus reducing the efficiency of the hydrofoil properties of the fin.Further, typical swim fins increase the footprint of the swimmer and areconstructed of heavy and bulky materials, thus making it difficult towalk, as is often necessary when entering or exiting water via ashoreline, a boat, or a dock.

Another major problem with typical swim fins is related to an integralfoot pocket which at least partially encloses the foot of the swimmer.Unfortunately, foot pockets tend to inadvertently gather foreign objectssuch as sand or gravel which can chafe the foot of the swimmer makingswimming and walking uncomfortable or even painful, and can further riskinfection. Further, foot pockets tend to retain some water which can beuncomfortable because the foot of the swimmer does not dry even when theswimmer is out of the water. Further, it can be difficult or impossibleto clear foreign objects or water from the foot pocket withoutcompletely removing the swim fin from the foot of the swimmer. Finally,foot pockets deprive the swimmer of the joyful sensation of walkingbare-footed across the warm sand of a sandy beach or the cool grass of agrassy lawn.

BRIEF SUMMARY OF INVENTION

A need therefore exists for a swim fin that eliminates theabove-described disadvantages and problems.

One aspect is a swim fin that includes an upper support frame, a lowersupport frame, a lower blade attached to the lower support frame, and atleast one hinge assembly connecting the upper support frame to the lowersupport frame. The upper support is configured to be generallypositioned along and attached to the front of a swimmer's lower legbetween the swimmer's knee and ankle The lower support frame isconfigured to extend, in a swimming position, from a position proximatethe swimmer's ankle to a position beyond the end of the swimmer's foot.The at least one hinge assembly allows the lower support frame to berotated upward from the swimming position to a walking position. Thewalking position enables the swimmer to walk barefoot on a surfacewithout the lower support frame nor the lower blade substantiallycontacting the surface.

Another aspect is a swim fin in which the upper support frame at leastpartially wraps around the front of the swimmer's lower leg.

Yet another aspect is a swim fin that also includes a pair of strapsconfigured to attach the upper support frame to the swimmer's lower leg.

Still another aspect is a swim fin that further includes paddingpositioned between the upper support frame and the front of theswimmer's lower leg and configured to make direct contact with theswimmer's lower leg.

Yet another aspect is a swim fin in which the lower support frameincludes two braces and a cross member. The two braces are configured tobe positioned on either side of the swimmer's foot and attached to theat least one hinge assembly. The cross member connects the two bracesand is configured to provide support to a portion of the lower bladethat is configured to make contact with the top (dorsum) of theswimmer's foot during a down strike while swimming.

A further aspect is a swim fin in which the upper support frame includestwo braces and two cross members connecting the two braces. The twobraces are configured to be positioned on either side of the swimmer'slower leg and attached to the at least one hinge assembly.

A still further aspect is a swim fin that includes a spring configuredto automatically rotate the lower support frame from the swimmingposition to the walking position.

Still yet another aspect is a swim fin that includes a dampenerconfigured to dampen the automatic rotation of the lower support framefrom the swimming position to the walking position.

A further aspect is a swim fin in which the at least one locking hingeassembly is configured to lock in the swimming position.

A still further aspect is a swim fin in which the at least one lockinghinge assembly is further configured to lock the lower support frame inany one of multiple swimming positions.

A yet further aspect is a swim fin that includes an upper support frame,a lower support frame, a lower blade attached to the lower supportframe, and at least one locking hinge assembly connecting the uppersupport frame to the lower support frame. The upper support frame isconfigured to be generally positioned along and attached to the front ofa swimmer's lower leg. The lower support frame is configured to extend,in a swimming position, from a position proximate the swimmer's ankle toa position beyond the end of the swimmer's foot. The at least one hingeassembly allows the lower support frame to be rotated upward from alocked swimming position to a locked walking position.

Another aspect is a swim fin in which the at least one hinge assemblyfurther include spring-loaded release buttons that are configured tounlock the at least one hinge assembly when depressed.

Still another aspect is a swim fin in which at least one hinge assemblyis further configured to lock the lower support frame in any one ofmultiple swimming positions.

Still another aspect is a swim fin that includes an upper support frame,a lower support frame, a lower blade attached to the lower supportframe, and at least one hinge assembly connecting the upper supportframe to the lower support frame. The upper support frame is configuredto be generally positioned along and attached to the front of aswimmer's lower leg. The lower support frame is configured to extend, ina swimming position, from a position proximate the swimmer's ankle to aposition beyond the end of the swimmer's foot. The at least one hingeassembly includes a spring. The spring is configured to automaticallyrotate the lower support frame from a walking position to a swimmingposition.

Another aspect is a swim fin that includes a latch configured to retainthe lower support frame in the walking position.

Still another aspect is a swim fin in which the latch is attached to theupper support frame and engages the lower support frame or the latch isattached to the lower support frame and engages the upper support frame.

Yet another aspect is a swim fin which includes a dampener configured todampen the automatic rotation of the lower support frame from thewalking position to the swimming position.

Still another aspect is a swim fin in which the spring is furtherconfigured to generally maintain the lower support frame in the swimmingposition even during the upstroke of the swimmer's leg.

These and other aspects, features and advantages of the invention willbecome more fully apparent from the following detailed description ofpreferred embodiments and appended claims.

BRIEF DESCRIPTION OF DRAWINGS

The appended drawings contain figures of preferred embodiments tofurther clarify the above and other aspects, advantages and features ofthe invention. It will be appreciated that these drawings depict onlypreferred embodiments of the invention and are not intended to limit itsscope. The invention will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1A is a perspective view of an example swim fin in a swimmingposition strapped to the leg of a swimmer;

FIG. 1B is a side view of the example swim fin of FIG. 1A in a walkingposition;

FIG. 1C is an exploded perspective view of the example swim fin of FIG.1A in the swimming position disclosed in FIG. 1A;

FIG. 2A is a perspective view of a second example swim fin in a swimmingposition strapped to the leg of a swimmer;

FIG. 2B is a side view of the example swim fin of FIG. 2A in a walkingposition; and

FIG. 2C is an exploded perspective view of the example swim fin of FIG.2A in the swimming position disclosed in FIG. 2A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

It will be readily understood that the components of the presentinvention, as generally described and illustrated in the Figures herein,could be arranged and designed in a wide variety of differentconfigurations. Thus, the following more detailed description ofpreferred embodiments is not intended to limit the scope of theinvention, as claimed, but it is merely representative of some of thepresently preferred embodiments of the present invention.

The present invention is generally directed towards swim fins that areworn on the foot of a swimmer to aid movement through the water whilesurface swimming or participating in swimming-related activities such asbodyboarding, bodysurfing, kneeboarding, riverboarding, snorkeling, andvarious types of underwater diving. The swim fins disclosed herein arealso specifically designed to be worn by the swimmer while the swimmeris walking in shallow water or out of the water such as on a beach, aboat, or a dock, for example, without interfering with the stride of theswimmer.

Additionally, to assist in the description of the swim fins, words suchas top, bottom, front, rear, right, left, up, and down are used todescribe the accompanying figures, which are not necessarily drawn toscale. It will be appreciated, however, that the present invention canbe located in a variety of desired positions—including various angles,sideways and even upside down. A detailed description of the swim finsnow follows. As discussed below and shown in the accompanying figures,the swim fins may be worn by a swimmer in a “swimming position” whileswimming as well in a “walking position” while walking along in or outof the water. This dual-functionality avoids the time and hassle ofhaving to remove the swim fins in order to transition from swimming towalking The dual-functionality also enables the swimmer to comfortablywear the swim fins well in advance of entering the water to swim, evenwhen the swimmer must walk short or long distances before entering thewater to swim. Further, the swim fins allow the swimmer to comfortablywear the swim fins even while wearing other footwear, such as sandals orwater socks, for example.

First Example Swim Fin

As disclosed in FIGS. 1A, 1B, and 1C, a first example swim fin 100generally includes an upper support frame 102, a lower support frame104, a lower blade 106 attached to the lower support frame 104, and apair of hinge assemblies 108 and 110 connecting the upper support frame102 and the lower support frame 104. The hinge assemblies 108 and 110connect the upper support frame 102 to the lower support frame 104 andallow the lower support frame 104 to be rotated upward from a “swimmingposition,” disclosed in FIG. 1A, to a “walking position,” disclosed inFIG. 1B, while the upper support frame 102 remains securely attached tothe lower leg 302 of a swimmer 300. The swimming position disclosed inFIG. 1A enables the swimmer 300 to swim through water with increasedthrust as compared to swimming with a bare foot. The walking positiondisclosed in FIG. 1B enables the swimmer 300 to walk on a surface 400without the swim fin substantially contacting the surface 400 andwithout the swim fin 100 interfering with the stride of the swimmer 300.

As disclosed in FIG. 1A, in the swimming position, the lower supportframe 104 and the lower blade 106 are configured to generally extendfrom the front of the swimmer's ankle 304 to a position beyond the endof the swimmer's foot 306. As disclosed in FIG. 1B, in the walkingposition, the lower support frame 104 and the lower blade 106 areconfigured to generally extend from the front of the swimmer's ankle 304to a position proximate the swimmer's knee (not shown).

As disclosed in FIGS. 1A, 1B, and 1C, the upper support frame 102 isconfigured to be generally positioned along the front of lower leg 302of a swimmer 300 between the knee (not shown) and the ankle 304. Theupper support frame 102 generally includes two braces 112 and 114 andtwo cross members 116 and 118. The braces 112 and 114 are configured tobe positioned on either side of the swimmer's lower leg 302. The braces112 and 114 are also configured to be attached to the hinge assemblies108 and 110, respectively. The cross members 116 and 118 connect andsupport the braces 112 and 114. The cross members 116 and 118 mayfurther be configured to at least partially wrap around the front of theswimmer's lower leg 302.

The upper support frame 102 is configured to be securely attached to theswimmer's lower leg 300, instead of to the swimmer's heel 308. Forexample, the upper support frame 102 may further include a pair ofstraps 120 and 122 configured to attach the upper support frame 102 tothe front of the swimmer's lower leg 300. The straps 120 and 122 may beadjustable straps to accommodate multiple swimmers with variously sizedlower legs. For example, each of the straps 120 and 122 may include abuckle, Velcro®, a rachet buckle, or other adjustable fastener toaccommodate various sizes of lower legs. The straps may be formed fromvarious materials or combinations of materials including, but notlimited to, polychloroprene.

The upper support frame 102 can be constructed, by molding for example,from a relatively rigid substance, such as a relatively rigid plastic,in order to provide structural support to the hinge assemblies 108 and110. It is understood, however, that portions of the upper support frame104, such as middle portions of the braces 112 and 114, may beconstructed from a less rigid substance in order to allow the uppersupport frame 102 to fit snuggly against the swimmer's lower leg 302during swimming and walking

As disclosed in FIG. 1C, the swim fin 100 may further include padding124 positioned between at least portions of the upper support frame 102and the front of the swimmer's lower leg 302. The padding 124 isconfigured to make direct contact with the swimmer's lower leg 302 andcushion the force of the braces 112 and 114 and the cross members 116and 118 of the upper support frame 102 against the swimmer's lower leg302 as the straps 120 and 122 are tightened. The padding can be formed,by stamping for example, from a soft and comfortable material, such aspolychloroprene.

As disclosed in FIGS. 1A and 1C, the lower support frame 104 generallyincludes two braces 126 and 128 and a cross member 130 a. The braces 126and 128 are configured to be positioned on either side of the swimmer'sfoot 306. The braces 126 and 128 are also configured to be attached tothe hinge assemblies 108 and 110, respectively. The cross member 130 aconnects and supports the braces 126 and 128. The cross member 130 a mayfurther be configured to provide support to a portion of the lower blade106 that is configured to make contact with the top (dorsum) of theswimmer's foot 306 during a down stroke while swimming. Advantageously,the cross member 130 a enables the swimmer's foot 306 to contributeforce to the down stroke of the swim fin 100 without any portion of theswim fin 100 being attached to the swimmer's foot 306. The cross member130 a may alternatively be positioned to avoid contact with top (dorsum)of the swimmer's foot 306 during the down stroke so that the entireforce of the down stroke is provided by the swimmer's lower leg 302,thus allowing the swimmer's ankle 304 and foot 306 to generally remainat rest while swimming. For example, additional padding 124 can bepositioned near the lower portion of the upper support frame 102,beneath the cross member 118 for example, in order to tilt the lowersupport frame 104 further away from the swimmer's foot 306. Further, thecross member 130 a can be curved upward away from the swimmer's foot 306to avoid contact with the swimmer's foot 306 during a down stroke.

The lower support frame 104 can be constructed, by molding for example,from a relatively rigid substance, such as a relatively rigid plastic,in order to provide structural support to the blade 106 and the hingeassemblies 108 and 110. It is understood, however, that portions of thelower support frame 104, such as lower portions of the braces 126 and128, may be constructed in such a way as to allow these portions to flexup (during a down stroke) and down (during an up stroke) while swimming.For example, the cross section of braces 126 and 128 could be generallyrectangular, and the upper and lower sides of the braces 126 and 128 canbe grooved to facilitate flexion in the upward and downward directions.Alternatively, or additionally, portions of the braces 126 and 128 canbe constructed from a less rigid substance in order to allow theseportions to flex up and down during swimming. In at least some exampleembodiments, the flexible portions of the braces 126 and 128 enable thelower support frame 104 to flex up and down, but avoid enabling thebraces 126 and 128 to flex inward or side to side. For example, thecross member 130 a can support the braces 126 and 128 in order to avoidthe braces 126 and 128 from flexing inward toward one another or outwardaway from one another. Further, the function of the cross member 130 acan be augmented by one or more additional cross members, as disclosedbelow in connection with FIGS. 2A, 2B, and 2C.

The blade 106 can be formed from a relatively light and flexiblematerial, such as a relatively flexible vinyl, silicon, rubber, orrubberized rip-stop nylon material, in order to allow the blade 106 toflex during swimming. Furthermore, the blade 106 may be made from apartially or totally transparent material in order to avoid impeding theview of the swimmer 300 during walking Further, the blade 106 mayincorporate hydrofoil chutes 106 a and 106 b that allow water to bepushed through the blade 106 in a direction that is generally inlinewith the forward motion of the swimmer 300. These chutes may be formedfrom a material that allows the chutes to transition from protrudingfrom the top surface of the blade 106 (during a down stroke) toprotruding from the bottom surface of the blade 106 (during an upstroke) in order to direct water propulsion and provide increasedforward thrust during both the up and down strokes while swimming.

As disclosed in FIG. 1C, the locking hinge assembly 108 includes anupper hinge member 108 a, a locking ring 108 b, a spring 108 c, a lowerhinge member 108 d, and a release button 108 e. The locking hingeassembly 110 similarly includes an upper hinge member 110 a, a lockingring 110 b, a spring 110 c, a lower hinge member 110 d, and a releasebutton 110 e. In operation, the locking hinge assemblies 108 and 110 areconfigured to automatically lock the lower support member in either theswimming position, disclosed in FIG. 1A, or in the walking position,disclosed in FIG. 1B.

The locking mechanisms 108 b and 110 b are configured to be unlocked bymanually pressing the release buttons 108 e and 110 e, respectively,thus disengaging the locking rings 108 b and 110 b, respectively, andallowing the lower support frame 104 to be rotated between the swimmingand walking positions. Once the lower support frame 104 is rotated toeither of the swimming or walking positions, the springs 108 c and 110 cautomatically reengage the locking rings 108 b and 110 b, respectively,thus automatically locking the lower support frame 104 with respect tothe upper support frame 102.

Second Example Swim Fin

With reference now to FIGS. 2A, 2B, and 2C, a second example swim fin100′ is disclosed. The swim fin 100′ is identical to the swim fin 100,with the exception of the lower support frame 104′, the blade 106′, thehinge assemblies 108′ and 110′ and a latch 132.

As disclosed in FIGS. 2A, 2B, and 2C, the lower support frame 104′includes an additional cross member 130 b that augments the supportingfunction of the cross member 130 a by supporting the braces 126′ and the128′. Further, the blade 106′ incorporates hydrofoil chutes 106 c, 106d, and 106 e that allow water to be pushed through the blade 106′ in adirection that is generally inline with the forward motion of theswimmer 300. Like the chutes 106 a and 106 b, the chutes 106 c, 106 d,and 106 e may be formed from a material that allows the chutes totransition from protruding from the top surface of the blade 106 (duringa down stroke) to protruding from the bottom surface of the blade 106(during an up stroke) in order to direct water propulsion and provideforward thrust during both the up and down strokes while swimming.

It is understood that the sizes, positions, and shapes of the hydrofoilchutes 106 a-106 e disclosed in FIGS. 1A-2C are example numbers, sizes,positions, and shapes only. Other sizes, positions, and shapes ofhydrofoil chutes are possible and contemplated. For example, each of theblades 106 and 106′ can have zero or more hydrofoild chutes. Further,the size of the hydrofoild chutes on the blades 106 and 106′ can besmaller or larger than the chutes disclosed in FIGS. 1A-2C. Also, thepositions of the hydrofoil chutes can vary from the positions disclosedin FIGS. 1A-2C. Finally, the shapes of the openings of the hydrofoilchutes can differ from the generally parabolic shape disclosed in FIGS.1A-1C and the generally rectangular shape disclosed in FIG. 2A-2C. Forexample, the shapes of the hydrofoil chutes can be triagonal,trapezoidal, square, or pentagonal, for example. The openings of thehydrofoil chutes can also have any of a variety of different shapes.

As disclosed in FIGS. 2A and 2B, the braces 126′ and 128′ are bentforward to a greater degree than the braces 126 and 128 disclosed inFIG. 1B. The shape of the braces 126′ and 128′ also causes the shape ofthe blade 106′ to bend forward to a greater degree than the blade 106.The shape of the braces 126′ and 128′ and the blade 106′ allow the swimfin 100′ to function properly while swimming with less forward rotationof the swimmer's ankle 304 than is required by the swim fin 100.

As disclosed in FIG. 2C, the example swim fin 100′ includes modifiedhinge assemblies 108′ and 110′, as well as a latch 132. Unlike the hingeassemblies 108 and 110, the hinge assemblies 108′ and 110′ are notlocking hinge assemblies. Instead, the hinge assembly 108′ includes adampener 108 f and the hinge assembly 110′ includes a power spring 110 fThe power spring 110 f is biased to automatically rotate the lowersupport frame 104′ from the walking position to the swimming position.The power spring 110 f is further configured to generally maintain thelower support frame 104 in the swimming position both during theupstroke and the downstroke of the swimmer's lower leg 302, but withoutrigidly locking the hinge assembly 110′. Accordingly, unlike therelatively rigid locking hinge assembly 110, the hinge assembly 110′allows the lower support frame 104′ to automatically rotate upward ifthe swimmer 300 stands on the swim fin 100′ in the swimming positionwithout bending or otherwise damaging the lower support frame 104′and/or the hinge assemblies 108′ and 110′ of the swim fin 100′. Thedampener 108 f is configured to dampen the force of the power spring 110f while the lower support frame 104′ is automatically rotating from thewalking position to the swimming position such that the rotation is moregradual and less abrupt.

The bias of the power spring 110 f can be overcome by the swimmergrasping the lower support frame 104′ in the swimming position androtating the lower support frame 104′ to the walking position, at whichpoint in time the lower support frame 104′ automatically engages withthe latch 132. As disclosed in FIGS. 2A and 2B, the latch 132 isattached to the cross member 118 of the upper support frame 102 and isconfigured to engage with the cross member 130 a of the lower supportframe 104′ in order to retain the lower support frame 104′ in thewalking position. The latch 132 is stationary and allows the crossmember 130 a to slip under the latch 132 by manually flexing the crossmember 118 and/or the cross member 130 a.

Alternatively, the latch 132 can be configured to slide up and down andbe spring loaded to bias the latch 132 down in front of the cross member130 a, as disclosed in FIG. 2B. As the lower support frame 104′ ismanually rotated up to the walking position by the swimmer 300, theswimmer 300 can simultaneously manually slide the latch 132 up to allowthe cross member 130 a to slip under the latch 132 and then release thelatch 132 to automatically allow latch 132 to slide back down to retainthe lower support frame 104′ in the walking position.

Although the latch 132 is attached to the cross member 118 of the uppersupport frame 102, it is understood that the latch 132 could instead beattached to the cross member 130 a of the lower support frame 104′.Further, it is understood that in at least some example embodiments, thelatch 132 can be omitted altogether. For example, the cross member 118and 130 a can instead be configured and positioned to overlap and engageone another by slipping the cross member 130 a under the cross member118 by manually flexing the cross member 118 and/or the cross member 130a.

As disclosed in FIGS. 2A and 2B, the hinge assemblies 108′ and 110′ aregenerally positioned proximate the swimmer's ankle 304. However, it isunderstood that the hinge assemblies 108′ and 110′ could instead bepositioned further up the swimmer's lower leg 302 or further down theswimmer's foot 306. It is further noted that the lower blade 106′ canalso include an opening through which at least a portion of theswimmer's foot 306 or toes can protrude to enable the braces 126′ and128′ and the blade 106′ to have less curvature and better align with theswimmer's lower leg 302.

Alternative Swim Fins

In at least some alternative embodiments, aspects of the swim fins 100and 100′ can be modified and/or combined. For example, the power spring110 f can be reversed in order to automatically rotate the lower supportframe 104′ from the swimming position to the walking position, and thedampener 108 f can be reversed to dampen the force of the reversed powerspring 110 f. In this alternative embodiment, locking aspects of thelocking hinge assemblies 108 and 110 can be employed to allow modifiedhinge assemblies 108′ and 110′ to lock in the swimming position. Theunlocking of the modified hinge assemblies 108′ and 110′ can thereforeresult in the reversed power spring 110 f causing the automatic rotationof the lower support frame 104′ from the swimming position to thewalking position. The latch 132 can be omitted in this alternativeembodiment as the reversed power spring 110 f will generally maintainthe lower support frame 104′ in the walking position. Further, a ratchetmechanism can be included in the modified hinge assemblies 108′ and 110′in order to allow the swimmer 300 to ratchet the lower support frame104′ to a position between the walking and swimming positions, and thento begin swimming in order to allow the rachet mechanism to complete therotation of the lower support frame 104′ into the swimming position.

In another alternative embodiment, the locking hinge assemblies 108 and110 can be configured to lock the lower support frame 104 in one ofmultiple swimming positions and/or one of multiple walking positions.For example, in a first swimming position, the cross member 130 a can beconfigured to provide support to a portion of the lower blade 106 thatis configured to make contact with the top (dorsum) of the swimmer'sfoot 306 during a down stroke while swimming. In a second swimmingposition, the cross member 130 a can be configured and positioned toavoid contact with the top (dorsum) of the swimmer's foot 306 during adown stroke while swimming. In this alternative embodiment, manuallypressing the release buttons 108 e and 110 e disengages the lockingrings 108 b and 110 b, respectively, and allows the lower support frame104 to be rotated to the next of the multiple swimming or walkingpositions. It is understood that the release buttons can be replacedwith other release mechanisms that are positioned in other areas of theswim fin 100. For example, one or more release mechanisms can bepositioned on the upper support frame 102 in order to allow the releaseof the locking mechanisms 108 and 110 to be accomplished by the swimmer300 without reaching all the way down to the swimmer's ankle 304.Further, one or more release mechanisms can be positioned on lowersupport frame 104 in order to allow the release mechanism(s) to bereleased by the heel of the swimmer's other foot.

It is understood that although a pair hinge assemblies are disclosed inconnection with each of the swim fins 100 and 100′, the functionality ofthe pair of hinge assemblies could instead be combined into a singlehinge assembly, or could be distributed across three or more hingeassemblies. Accordingly, example embodiments of the invention are notlimited to any particular number of hinge assemblies. It is furtherunderstood that the functionality of any of the hinge assembliesdisclosed herein can be combined with the functionality of any otherhinge assembly disclosed herein in order to provide one or more hingeassemblies with multiple functionalities. For example, the power spring110 f and the dampener 108 f can be combined into a single hingeassembly.

It is understood that the lower support frames and the lower bladesdisclosed herein can, in at least some embodiments, be formed as asingle component and/or from a single material.

The example swim fins disclosed herein thus allow the lower supportframe to be quickly and easily placed in the swimming position to allowa swimmer to swim and in the walking position to allow the swimmer towalk. By attaching only to the lower leg of the swimmer, instead of tothe foot and heel, the swim fins disclosed herein cause less anklestrain and calf muscle fatigue than typical swim fins. Further,attaching to the leg instead of to the foot and heel of the swimmerallows the swim fins disclosed herein to avoid the problems associatedwith rotational movement of the ankle joint and to consistently propelthe swimmer in a direction that is aligned with the direction of theswimmer's legs and torso. In addition, once rotated to the walkingposition, the swim fins disclosed herein can remain attached to theswimmer's leg without increasing the footprint of the swimmer, thusmaking the swim fins ideal for walking when entering or exiting watervia a shoreline, a boat, or a dock. Also, the relatively light bladeportion of the swim fins disclosed herein is less heavy and less bulkythan the materials from which typical swim fin blades are made, makingthe swim fins less cumbersome for use when the swimmer is out of thewater. The swim fins disclosed herein also have relatively efficienthydrofoil properties. These advantages of the swim fins disclosed hereinare accomplished without the integral foot pocket included in typicalswim fins, and thus the problems associated with foot pockets listedherein are completely avoided. Further, unlike users of typical swimfins, a swimmer can wear the swim fins disclosed herein in the walkingposition and simultaneously experience the joyful and uninhibitedsensation of walking bare-footed across the warm sand of a sandy beachor the cool grass of a grassy lawn.

Although this invention has been described in terms of certain preferredembodiments, other embodiments apparent to those of ordinary skill inthe art are also within the scope of this invention. Accordingly, thescope of the invention is intended to be defined only by the claimswhich follow.

1. A swim fin comprising: an upper support frame configured to begenerally positioned along and attached to the front of a swimmer'slower leg between the swimmer's knee and ankle; a lower support frameconfigured to extend, in a swimming position, from a position proximatethe swimmer's ankle to a position beyond the end of the swimmer's foot;a lower blade attached to the lower support frame; and at least onehinge assembly connecting the upper support frame to the lower supportframe and configured to be positioned proximate the swimmer's ankle,wherein the at least one hinge assembly allows the lower support frameto be rotated upward from the swimming position to a walking position,the walking position enabling the swimmer to walk barefoot on a surfacewithout the lower support frame nor the lower blade substantiallycontacting the surface.
 2. The swim fin as in claim 1, wherein the uppersupport frame at least partially wraps around the front of the swimmer'slower leg and includes an upper blade attached to the upper supportframe.
 3. The swim fin as in claim 2, further comprising: a pair ofstraps configured to attach the upper support frame to the swimmer'slower leg;
 4. The swim fin as in claim 3, further comprising: paddingpositioned between the upper support frame and the front of theswimmer's lower leg and configured to make direct contact with theswimmer's lower leg.
 5. The swim fin as in claim 1, wherein the lowersupport frame comprises: two braces configured to be positioned oneither side of the swimmer's foot and attached to the at least one hingeassembly; and a cross member connecting the two braces, the cross memberconfigured to provide support to a portion of the lower blade that isconfigured to make contact with the top (dorsum) of the swimmer's footduring a down strike while swimming.
 6. The swim fin as in claim 1,wherein the upper support frame comprises: two braces configured to bepositioned on either side of the swimmer's lower leg and attached to theat least one hinge assembly; and two cross members connecting the twobraces.
 7. The swim fin as in claim 1, further comprising: a springconfigured to automatically rotate the lower support frame from theswimming position to the walking position.
 8. The swim fin as in claim7, further comprising: a dampener configured to dampen the automaticrotation of the lower support frame from the swimming position to thewalking position.
 9. The swim fin as in claim 8, wherein the at leastone hinge assembly is configured to lock in the swimming position. 10.The swim fin as in claim 9, wherein the at least one locking hingeassembly is further configured to lock the lower support frame in anyone of multiple swimming positions.
 11. A swim fin comprising: an uppersupport frame configured to be generally positioned along and attachedto the front of a swimmer's lower leg; a lower support frame configuredto extend, in a swimming position, from a position proximate theswimmer's ankle to a position beyond the end of the swimmer's foot; alower blade attached to the lower support frame; and at least onelocking hinge assembly connecting the upper support frame to the lowersupport frame, wherein the at least one locking hinge assembly allowsthe lower support frame to be rotated upward from a locked swimmingposition to a locked walking position.
 12. The swim fin as in claim 11,wherein the at least one locking hinge assembly further comprises atleast one spring-loaded release button that is configured to unlock theat least one locking hinge assembly when depressed.
 13. The swim fin asin claim 11, wherein the at least one locking hinge assembly is furtherconfigured to lock the lower support frame in any one of multipleswimming positions.
 14. The swim fin as in claim 11, wherein the walkingposition enables the swimmer to walk barefoot on a surface without thelower support frame nor the lower blade substantially contacting thesurface.
 15. A swim fin comprising: an upper support frame configured tobe generally positioned along and attached to the front of a swimmer'slower leg; a lower support frame configured to extend, in a swimmingposition, from a position proximate the swimmer's ankle to a positionbeyond the end of the swimmer's foot; a lower blade attached to thelower support frame; and at least one hinge assembly connecting theupper support frame to the lower support frame, the at least one hingeassembly including a spring, the spring configured to automaticallyrotate the lower support frame from a walking position to a swimmingposition.
 16. The swim fin as in claim 15, further comprising: a latchconfigured to retain the lower support frame in the walking position.17. The swim fin as in claim 16, wherein: the latch is attached to theupper support frame and engages the lower support frame; or the latch isattached to the lower support frame and engages the upper support frame.18. The swim fin as in claim 15, further comprising a dampenerconfigured to dampen the automatic rotation of the lower support framefrom the walking position to the swimming position.
 19. The swim fin asin claim 15, wherein the spring is further configured to generallymaintain the lower support frame in the swimming position during anupstroke of the swimmer's leg.
 20. The swim fin as in claim 15, whereinthe walking position enables the swimmer to walk barefoot on a surfacewithout the lower support frame nor the lower blade substantiallycontacting the surface.